1. Field of the Invention
The present invention relates to a brush for the application of a make-up product such as a nail varnish, a liquid make-up for the lips, or a liquid make-up foundation, of the kind which comprise bristles disposed substantially parallel to each other in a tuft and fixed on a support herein called a brush stem. It also relates to a unit for the application of a nail varnish.
2. Discussion of the Background
The conventional brushes for applying nail varnish generally have a tuft of approximately 600 bristles with a diameter of 0.08 mm which are made most frequently of polyamide, for instance of nylon 6, 6-6, 6-10, 6-12, of nylon 11 or of polyester.
The make-up brushes currently developed leave much to be desired as regards to the precision and speed of making-up, in particular during the application of a varnish to the nails.
Moreover, with a conventional make-up brush, it is often necessary to dip the brush several times into the container containing the product in order to effect the making up of the nails, one after the other, since the quantity of the product taken up by the brush is relatively small.
Various technological solutions have been proposed to cope with this drawback, for example by incorporating a kind of reservoir in the brush stem. However, these technological solutions to the problem complicate the manufacture and the use of the brush. Furthermore, these solutions to the problem are relatively expensive. Moreover, it has been found that by increasing the diameter of the polyamide brush bristles, and reciprocally by reducing their number, see in particular FR-A 2 687 055, one could increase the interstices between the bristles and, as a result, obtain a greater product charge and greater inherent capacity for the brush. However, it has been found that during the application of a nail varnish this brush spreads insufficiently on the surface to be treated, and that it forms striae in the layer of varnish deposited on the nail, which is in no way desirable from an aesthetic point of view. In this case, it has been found that the brush pushes the product over the surface.
The aim of the present invention is to provide a make-up brush which makes it possible to remedy these disadvantages. In particular, this brush should ensure a precise application of make-up while carrying far more of the product than a conventional brush, and have a greater inherent capacity than the conventional brushes making it possible to deposit a more substantial layer thickness, resulting in greater ease of application as far as the user is concerned.
After numerous tests, it has been found that by the judicious adjustment of certain characteristics of a make-up brush, one could surprisingly obtain a more homogeneous application of a layer of the make-up product, in particular when the brush is intended for the application of nail varnish. Moreover, the layer of varnish obtained after drying has a better mechanical strength than that according to the prior art and has a better adhesion on the nail.
It has been observed that by adjusting the hardness of the bristles within a very precise range, and if necessary, by increasing their diameter, it is possible to obtain a nail varnish brush which has a product loading capacity superior to that of the conventional brushes, and hence a greater inherent capacity. It is also possible to expand the viscosity range of the varnish over that of conventionally used varnishes, thus opening the way for new and original nail varnish compositions. Also it is possible to obtain a varnish surface on the nail that is more homogeneous and thicker, without the formation of striae.
It has, surprisingly, been found that the appearance of the make-up thus obtained was shinier, and that the mechanical strength of the applied layer, after drying, as well as the solidity of the adhesion of the varnish on the nail were increased. It has, moreover, been found that the new brush in accordance with the invention is capable of drawing the varnish over the surface to be treated, instead of pushing it.